Since Unimate, which is the first industrial robot used for an assembly process in 1962, has been introduced, robot engineering has been established as an essential technology in production, service, medical, exploration, military, and aerospace fields in view of quick technical development and expansion of application fields.
The existing robot has been intended to precisely perform simple repeated work at a high speed, but recently, robots with various manners and various levels, such as a robot which is remotely connected and shares an activity space with humans, a surgical robot which easily performs various operations such as a laparoscopic surgery, and an industrial robot which enables safe physical contact with a human, are being developed.
In addition, in the case of a Baxtor robot, which is developed recently, receives the attention as a next-generation robot which has a function of detecting and adapting to force from a user, enables the user to perform an action while directly moving the robot, and enables cooperation between the human and the robot in the same workspace.
However, the Baxtor robot sacrifices strength, rigidity, precision, and working speed in order to ensure safety, and as a result, there is a problem in that performance thereof deteriorates in comparison with the existing industrial robots.
Therefore, there is a need for a technology about a robot which may detect external force, ensure safety at the time of contact and collision, and satisfy high strength, rigidity, precision, and working speed.
To this end, a technology of implementing a joint of the robot similar to a human's arm having a high degree of freedom become a serious issue as a key research task, and actually, research results reflecting outcomes thereof are being reported.
However, a robot joint structure, which has been researched up to now, has a problem in that a structure thereof is very complicated in order to ensure a multi-degree of freedom and sufficient strength and rigidity, and performance inevitably deteriorates when simplifying the structure.
Accordingly, there is a need for a method for solving the aforementioned problems.